CHICAGO (AP) – After failing to persuade a majority of Chicago voters to back his re-election bid, Mayor Rahm Emanuel could face an even stiffer challenge in April against a runoff opponent aiming to consolidate the support of residents unhappy with how the former White House chief of staff has managed the nation's third-largest city.

In a race Tuesday against four challengers, Emanuel discovered it wasn't enough to spend millions of dollars on TV ads, earn the backing of the city's business leaders, and secure the hometown endorsement of President Barack Obama. In order to keep the job, he'll need to win another race in six weeks against Jesus "Chuy" Garcia, a Cook County commissioner who claims the backing of teachers, unions and neighborhood residents disillusioned with Emanuel.

"We will get back out there, talking to our friends and families and neighbors as they make a critical choice about who has the strength, who has the leadership, who has the ideas to move this great city forward," Emanuel told supporters Tuesday evening.

But Garcia and his supporters said they'd be ready for another contest, with national groups poised to weigh in on the mayor's race.

"This city deserves a mayor who will put people first, not big money, special interests," Garcia said. "I will be that mayor."

Garcia, born in Mexico and raised in Chicago, billed himself as the "neighborhood guy." He drew on his contacts with community organizers and support from the Chicago Teachers Unions, whose leader, Karen Lewis, considered a mayoral bid before being diagnosed with a brain tumor.

With nearly all the votes counted, Emanuel had 45 percent, Garcia 34 percent, and the three other candidates divided the rest.

During the campaign, Garcia and the three other challengers played on discontentment in Chicago's neighborhoods, where frustrations linger over Emanuel's push to close dozens of schools. They also criticized Emanuel's roughly $16 million fundraising operation — more than four times his challengers combined — and attention to downtown improvements.

The American Federation of Teachers said the election showed "a real yearning" for a mayor who listens to working families. Also, at least one of Emanuel's other challengers — businessman Willie Wilson who captured more than 10 percent of the vote — said he wanted to meet with Garcia.

Garcia, Wilson and the other challengers — Alderman Bob Fioretti and activist William Walls — also critiqued the mayor on his handling of violence.

Voters noted both issues at the polls, with estimates signaling lower turnout than 2011 after former Mayor Richard Daley retired, leaving the mayor's race wide open. About 42 percent of eligible voters came to the polls then, compared with roughly 34 percent Tuesday.

Emanuel won his first mayoral race in 2011 without a runoff.

Joyce Rodgers, who is retired, said she believed the school closings cost Emanuel the trust of the African-American community — and possibly the president's. Most Chicago Public Schools students are minorities.

"There is total disappointment (in Emanuel)," she said. "I believe that Obama's been let down, too, he's just not going to say it."

Still others said they were supporting Emanuel because of his work on job creation, education and safer neighborhoods.

"Rahm has all (those) contacts and he is getting those corporations here, so he is giving people hope they can get a good job," said Willie King, a 56-year-old retired janitor.

On the campaign trail, Emanuel said his first term saw some tough decisions and payoffs, including budgets that didn't rely on property tax increases, drawing business to the city, getting a longer school day and raising the minimum wage.

"We have come a long way, and we have a little bit further to go," Emanuel told supporters.